1. Field of the Invention
The present invention relates generally to a valve position indicator and more particularly to a position indicator that is constructed in a simple manner so as to clearly indicate both the number of turns and the degree of rotation of any given rotation of the valve stem to which the handle is mounted.
2. Description of the Prior Art
As is well known in the art, various problems and difficulties are encountered in providing suitable means for indicating the position of a valve stem in a valve. Many types of handles have been tried and suggested. However, these devices have various limitations that restrict their use to specifically designed valve apparatuses. That is, very often valve stem position-indicating devices are employed with high-technology type valves that are in themselves very complicated to operate, and thus are not suitable for most commonly used valve structures. Moreover, some types of handles that are employed to position valve stems are complicated, not only to operate, but are complicated in their structural arrangement, and thus become too expensive for use in simple fluid-flow systems that operate under conditions that require close examination or manual testing to determine the position of a valve stem. In many fluid systems it is very important and critical to indicate if a valve is in an "Off" or "Closed" position, particularly if it can be accomplished by simply noting the position of the associated valve handle.
In many flow system the rate of flow is very important and it is not easy to tell whether or not a valve is in a proper position relative to a required flow rate. Thus, the position of the stem of a valve can also be a very critical factor. The proper positioning of a valve stem is at all times necessary, particularly when dangerous or valuable substances might be flowing through the pipes or conduits of a flow system controlled by a particular valve.
As an example of valve handles that are adapted to indicate the position of a valve stem, one may look to the following United States Patents.
In U.S. Pat. No. 3,910,308, there is disclosed a signal handle for valves that includes a handle portion provided with a knurled exterior and a plurality windows formed in recesses located between raised portions of the knurls. The windows are operatively associated with an indicia member that fits within the recessed body of the handle portion. This particular device is designed to only indicate an open or a closed valve-stem position.
In U.S. Pat. No. 2,599,286, there is disclosed a valve position indicator that is particularly applicable with valves for accurately graduating fluid flow on a desired basis, particularly microscopic flows, and is not suitable for use with simple valve stem structures as is the present invention.
As the art indicates, there is no valve handle or other valve position indicating device that incorporates the necessary components to provide a simple means to determine the position of a valve stem at any given point between an open and closed position within a valve, and still provide a valve handle that is universally adaptable for use with most common types of valves.